FIELD OF THE INVENTION
The invention lies in the field of optical connectors. In particular, the invention pertains to an end piece for a fiber-optic cable, which comprises at least one optical fiber, a sheath, and strength members.
In order to ensure uninterrupted protection against tensile stresses of an optical fiber, to be coupled to a fiber optic cable connector or housing, for example, of a fiber optic cable, strength members running in the cable are usually fixed to the plug or housing through special measures.
Such a fixture is disclosed, for example, in German published, non-prosecuted application DE 40 31 612 A1. There, stress fibers of a fiber-optic cable which is freed from its sheath at the end, which fibers serve as strength members, are fixed between a cylindrical rear connector extension and a sleeve pressed onto this extension. Since the sheath end is not fixed at the end itself, tensile forces acting on the sheath can pull the latter away axially from the connector extension. As a result, the stress fibers, and an optical fiber guided in the cable are partially exposed and subjected to environmental influences. It is thereby quite possible for the optical fiber to become damaged.
Another relatively complicated connection between a fiber optic cable and a connector is described in German published, non-prosecuted application DE 38 13 076 A1. Stress fibers and the sheath of the fiber-optic cable are commonly fixed by self-closure between a loose sleeve that is pushed under the stress fibers and the sheath, and an outer pinch sleeve. The sheath is firstly partially removed from the end of the cable, with the result that the stress fibers project beyond the sheath end. Subsequently, the projecting stress fibers are turned back over the sheath end and thereby cover the sheath on its outside. The pinch sleeve now pushed over this region is pressed onto the sleeve, already brought under the stress fibers, by applying a plurality of annular beads. It is thereby possible for the optical fiber guided in the loose sleeve in slotted longitudinal bores to become jammed.
U.S. Pat. No. 5,140,662 to Kumar describes a method of fastening an end of a fiber-optic cable end to a connector end piece without any adhesive. The rear end of the end piece has an insertion sleeve with a smaller outside diameter and an adjoining sleeve piece with a structured sheath surface and a larger outside diameter. An end of the optical fiber which is freed from its outer sheath in a fashion exposing stress elements is fixed in the insertion sleeve by crimping.
Subsequently, an outer crimping sleeve is pushed over the stress elements and crimped, thus fixing the stress elements.